Semiconductor lighting module package

ABSTRACT

A semiconductor lighting module package includes a substrate, a lead frame located on the substrate, and a semiconductor lighting element. The lead frame has a carrier portion and a connecting portion spaced from the carrier portion. The semiconductor lighting element is electrically connected with the carrier portion and the connecting portion respectively. A plurality of nanoscale reflectors are formed on the carrier portion. A plurality of nanoscale reflectors are formed on the connecting portion. Shapes of the nanoscale reflectors formed on the carrier portion are different from shapes of the nanoscale reflectors formed on the connecting portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation application of patentapplication Ser. No. 12/891,815, filed on Sep. 28, 2010, entitled“SEMICONDUCTOR LIGHTING MODULE PACKAGE,” and assigned to the sameassignee as this patent application. The parent application Ser. No.12/891,815 is based on and claims priority from Taiwan PatentApplication No. 099103137, filed in the State Intellectual PropertyOffice of Taiwan on Feb. 3, 2010. The disclosures of both relatedapplications are incorporated herein by reference in their entireties.

FIELD

The present disclosure generally relates to semiconductor lightingmodule packages, and particularly to a semiconductor lighting modulepackage with nanoscale reflectors.

BACKGROUND

Semiconductor lighting modules have many advantages, such as highluminosity, low operational voltage, low power consumption,compatibility with integrated circuits, easy driving, long-termreliability, and environmental friendliness, which have promoted thesemiconductor lighting modules as a widely used light source.

Reflection of commonly used semiconductor lighting modules is poor dueto light absorption, such that light extraction of the semiconductorlighting modules is reduced.

What is needed, therefore, is a semiconductor lighting module which canavoid reduction of the light extraction, and ameliorate the describedlimitations.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with referenceto the drawings. The components in the drawings are not necessarilydrawn to scale, the emphasis instead being placed upon clearlyillustrating the principles of the semiconductor lighting modulepackage. Moreover, in the drawings, like reference numerals designatecorresponding parts throughout the views.

FIG. 1A is a schematic cross section of a semiconductor lighting modulepackage in accordance with a first embodiment of the present disclosure.

FIG. 1B is a schematic top view of the semiconductor lighting modulepackage in accordance with the first embodiment, with a cover layerthereof being removed for clarity.

FIGS. 2A to 2C are schematic cross sections of a plurality of nanoscalereflectors of the semiconductor lighting module package of FIG. 1A.

FIGS. 3A to 3F are schematic cross sections of a plurality of nanoscalereflectors with modified structures.

FIG. 4A is a schematic cross section of a semiconductor lighting modulepackage in accordance with a second embodiment.

FIG. 4B is a schematic top view of the semiconductor lighting modulepackage in accordance with the second embodiment, with a cover layerthereof being removed for clarity.

FIG. 5 is a view similar to FIG. 4B, showing a semiconductor lightingmodule package in accordance with a third embodiment.

FIG. 6 is a view similar to FIG. 4B, showing a semiconductor lightingmodule package in accordance with a fourth embodiment.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures and components have notbeen described in detail so as not to obscure the related relevantfeature being described. Also, the description is not to be consideredas limiting the scope of the embodiments described herein. The drawingsare not necessarily to scale and the proportions of certain parts havebeen exaggerated to better illustrate details and features of thepresent disclosure.

Several definitions that apply throughout this disclosure will now bepresented.

The term “comprising,” when utilized, means “including, but notnecessarily limited to”; it specifically indicates open-ended inclusionor membership in the so-described combination, group, series and thelike.

FIGS. 1A and 1B show a semiconductor lighting module package 1 inaccordance with a first embodiment includes a substrate 10, a lead frame11, a semiconductor lighting element 12, a plurality of nanoscalereflectors 13, and a cover 14. The substrate 10 includes a first surface101 and a second surface 102 arranged on the two opposite sides of thesubstrate 10. The substrate 10 can be plastic, polymer, ceramic,silicon, metal, or a combination thereof.

The lead frame 11 is arranged on the first surface 101 of the substrate10 including a carrier portion 111 and a connecting portion 112. Thecarrier portion 111 is electrically insulated from the connectingportion 112. The lead frame 11 is made of copper or other electricallyconductive metal and is not limited to the shape shown in thisembodiment or any other particular shape.

The semiconductor lighting element 12 is arranged on the carrier portion111 of the lead frame 11 and electrically separately connected to theconnecting portion 112 and the carrier portion 111 by metal wires 16 aand 16 b. The semiconductor lighting element 12 emits light of at leastone first wavelength. The semiconductor lighting element 12 can be alight emitting diode, organic light emitting diode, or laser diode.

The plurality of nanoscale reflectors 13 is arranged separately on thefirst surface 101 of the substrate 10 and the lead frame 11 and can bealuminum or titanium formed by electron beam lithography orphotolithography. In this embodiment, a plurality of first nanoscalereflectors 13 a is arranged on the first surface 101 of the substrate10, a plurality of second nanoscale reflectors 13 b is arranged on thecarrier portion 111 of the lead frame 11, and a plurality of thirdnanoscale reflectors 13 c is arranged on the connecting portion 112 ofthe lead frame 11.

FIGS. 2A to 2C show the plurality of first nanoscale reflectors 13 a isarranged on the substrate 10 with a distance between every two of theplurality of first nanoscale reflectors 13 a having a distance P₀ and agap between every two of the plurality of first nanoscale reflectors 13a having a depth H₀. The plurality of second nanoscale reflectors 13 bare arranged on the carrier portion 111 with a distance between everytwo of the plurality of second nanoscale reflectors 13 b having adistance P₁ and a gap between every two of the plurality of secondnanoscale reflectors 13 b having a depth H₁. The plurality of thirdnanoscale reflectors 13 c is arranged on the connecting portion 112 witha distance between every two of the plurality of third nanoscalereflectors 13 c having a distance P₂ and a gap between every two of theplurality of third nanoscale reflectors 13 c having a depth H₂. In thisembodiment, the distances P₀, P₁, P₂ are all less than a half wavelengthof the visible light emitted by the lighting element 12 and arepreferably approximately 90 nm to approximately 130 nm. And a ratio ofthe depths H₀, H₁, H₂ over the distances P₀, P₁, P₂ respectively is notless than 2. The nanoscale reflectors 13 a, 13 b, 13 c are capable ofperforming subwavelength grating and the spacing of each of the gaps isless than half the wavelength of the visible light. The light generatedby the semiconductor lighting element 12 has at least a part which isreflected by the nanoscale reflectors 13 a, 13 b, 13 c. Each of thenanoscale reflectors 13 a, 13 b, 13 c has a reflective index exceedingthat of each of the substrate 10 and the lead frame 11.

FIGS. 3A to 3F show exemplary differently shaped nanoscale reflectors 13d to 13 i are provided, which are sequentially shaped as trapezoid,inverted trapezoid, elliptical, semicircular, pyramidical, invertedpyramidical. The nanoscale reflectors are rectangular in FIGS. 2A to 2C.The nanoscale reflectors can be at least one shape mentioned above or acombination thereof and not limited to them.

FIGS. 4A and 4B show a semiconductor lighting module package 2 inaccordance with a second embodiment includes a substrate 10, a leadframe 11, a semiconductor lighting element 12, a plurality of nanoscalereflectors 13, and a cover 14. The substrate 10 includes a first surface101 and a second surface 102 arranged on the two opposite sides of thesubstrate 10.

The lead frame 11 is arranged on the first surface 101 of the substrate10 including a carrier portion 111, a first connecting portion 112 a,and a second connecting portion 112 b. The carrier portion 111, thefirst connecting portion 112 a, and the second connecting portion 112 bare electrically insulated from each other. The lead frame 11 is made ofcopper or other electrically conductive metal and is not limited to theshape of this embodiment.

The semiconductor lighting element 12 is arranged on the carrier portion111 of the lead frame 11 and electrically connecting to the secondconnecting portion 112 b and the first connecting portion 112 aseparately with metal wires 16 a and 16 b. The semiconductor lightingelement 12 emits light of at least one first wavelength. Thesemiconductor lighting element 12 can be light emitting diode, organiclight emitting diode, or laser diode. The difference between thesemiconductor lighting module packages 1 and 2 is that the lead frame 11in the semiconductor lighting module package 2 is a structure ofdifferent thermal and electrical conduction pathway. The heat of thesemiconductor lighting element 12 of the semiconductor lighting modulepackage 2 is dissipated mainly through the carrier portion 111.

The plurality of nanoscale reflectors 13 are arranged separately on thefirst surface 101 of the substrate 10 and the lead frame 11 by electronbeam lithography or photolithography. In this embodiment, a plurality offirst nanoscale reflectors 13 a is arranged on the first surface 101 ofthe substrate 10, a plurality of second nanoscale reflectors 13 b isarranged on the carrier portion 111 of the lead frame 11, a plurality ofthird nanoscale reflectors 13 c is arranged on the first connectingportion 112 a of the lead frame 11, and a plurality of fourth nanoscalereflectors 13 j is arranged on the second connecting portion 112 b ofthe lead frame 11.

FIG. 5 shows a semiconductor lighting module package 3 in accordancewith a third embodiment includes a substrate 10, a lead frame 11, afirst semiconductor lighting element 12 a, a second semiconductorlighting element 12 b, and a plurality of nanoscale reflectors 13. Thesubstrate 10 includes a first surface 101 and a second surface (notshown) arranged oppositely on the two sides of the substrate 10.

The lead frame 11 is arranged on the first surface 101 of the substrate10 including a carrier portion 111, a first connecting portion 112 a,and a second connecting portion 112 b. The carrier portion 111, thefirst connecting portion 112 a, and the second connecting portion 112 bare electrically insulating with each other. The lead frame 11 is madeof copper or other electrically conductive metal and is not limited tothe shape shown in this embodiment.

The first semiconductor lighting element 12 a and the secondsemiconductor lighting element 12 b are arranged on the carrier portion111 of the lead frame 11 and electrically connecting to the carrierportion 111, the first connecting portion 112 a, and the secondconnecting portion 112 b by separate metal wires. The firstsemiconductor lighting element 12 a and the second semiconductorlighting element 12 b can emit light of the same or differentwavelengths. The first semiconductor lighting element 12 a and thesecond semiconductor lighting element 12 b can be light emitting diodes,organic light emitting diodes, or laser diodes.

The plurality of nanoscale reflectors 13 is arranged separately on thefirst surface 101 of the substrate 10 and the lead frame 11 by electronbeam lithography or photolithography. In this embodiment, a plurality offirst nanoscale reflectors 13 a is arranged on the first surface 101 ofthe substrate 10, a plurality of second nanoscale reflectors 13 b isarranged on the carrier portion 111 of the lead frame 11, a plurality ofthird nanoscale reflectors 13 c is arranged on the first connectingportion 112 a of the lead frame 11, and a plurality of fourth nanoscalereflectors 13 j is arranged on the second connecting portion 112 b ofthe lead frame 11.

FIG. 6 shows a semiconductor lighting module package 4 in accordancewith a fourth embodiment includes a substrate 10, a lead frame 11, afirst semiconductor lighting element 12 a, a second semiconductorlighting element 12 b, a third semiconductor lighting element 12 c, anda plurality of nanoscale reflectors 13. The first semiconductor lightingelement 12 a and the second semiconductor lighting element 12 b arearranged on the first carrier portion 111 a of the lead frame 11. Thethird semiconductor lighting element 12 c is arranged on the secondcarrier portion 111 b of the lead frame 11. The semiconductor lightingelements 12 a, 12 b, 12 c are electrically connecting to the carrierportions 111 a, 111 b and the connecting portions 112 a, 112 b, 112 cseparately by metal wires. In addition to the plurality of nanoscalereflectors 13 a, 13 b, 13 c, 13 j as mentioned above in FIG. 5, thisembodiment further comprises a plurality of nanoscale reflectors 13 marranged on the third connecting portion 112 c of the lead frame 11, anda plurality of nanoscale reflectors 13 k arranged on the second carrierportion 111 b of the lead frame 11. The semiconductor lighting elements12 a, 12 b, and 12 c can emit light of the same or differentwavelengths.

Each of the embodiments mentioned above can further comprise cover layer14 covering the semiconductor lighting element 12 and partial lead frame11 with material including silicon dioxide, epoxy, or other transparentmaterial. The cover layer 14 can further include light diffusingparticles (not shown) for improving light refraction. The cover layer 14can be formed on the first surface 101 of the substrate 10 by transfermolding or injection molding. Furthermore, the cover layer 14 canfurther comprise at least one wavelength converting element 15 excitedby light of a first wavelength and emitting light of a secondwavelength. The wavelength converting element 15 can be YAG, TAG,aluminate, silicate, nitride, oxynitride, phosphide, sulfide, or acombination thereof. Using FIGS. 1A-1B as example, the wavelengthconverting elements 15 are excited by the light generated by thesemiconductor lighting element 12 to generate a light having awavelength different from that of the light generated by thesemiconductor lighting element 12. Then the two lights with differentwavelengths are mixed together to generate a desired light color, forexample, white light to be emitted from the semiconductor lightingmodule package 1.

The embodiments shown and described above are only examples. Manydetails are often found in the art such as the other features of asemiconductor lighting module package. Therefore, many such details areneither shown nor described. Even though numerous characteristics andadvantages of the present technology have been set forth in theforegoing description, together with details of the structure andfunction of the present disclosure, the disclosure is illustrative only,and changes may be made in the detail, especially in matters of shape,size and arrangement of the parts within the principles of the presentdisclosure up to, and including the full extent established by the broadgeneral meaning of the terms used in the claims. It will therefore beappreciated that the embodiments described above may be modified withinthe scope of the claims.

What is claimed is:
 1. A semiconductor lighting module package,comprising: a substrate; a lead frame located on the substrate, the leadframe having a carrier portion and a connecting portion spaced from thecarrier portion; a semiconductor lighting element electricallyconnecting with the carrier portion and the connecting portionrespectively; and wherein a plurality of nanoscale reflectors are formedon the carrier portion, a plurality of nanoscale reflectors are formedon the connecting portion, and shapes of the nanoscale reflectors formedon the carrier portion are different from shapes of the nanoscalereflectors formed on the connecting portion.
 2. The semiconductorlighting module package of claim 1, wherein a plurality of nanoscalereflectors are formed on a surface of the substrate located between thecarrier portion and the connecting portion.
 3. The semiconductorlighting module package of claim 2, wherein shapes of the nanoscalereflectors formed on the substrate are different from shapes of thenanoscale reflectors formed on either the carrier portion or connectingportion.
 4. The semiconductor lighting module package of claim 1,wherein a distance between every two of the nanoscale reflectors has adistance which is less than a half wavelength of a visible light.
 5. Thesemiconductor lighting module package of claim 4, wherein a gap betweenthe every two of the plurality of nanoscale reflectors has a depth, anda ratio of the depth over the distance is not less than
 2. 6. Thesemiconductor lighting module package of claim 1, wherein the nanoscalereflectors are metal.
 7. The semiconductor lighting module package ofclaim 1, wherein the nanoscale reflectors are trapezoid, invertedtrapezoid, elliptical, semicircular, pyramidical, inverted pyramidicalor rectangular.
 8. A semiconductor lighting module package, comprising:a carrier portion; a first connecting portion; a second connectingportion; and a semiconductor lighting element, the carrier portion, thefirst connecting portion and the second connecting portion beingelectrically insulated from each other, the semiconductor lightingelement being arranged on the carrier portion and electrically connectedto the first connecting portion and the second connecting portionrespectively; wherein a plurality of nanoscale reflectors are formed onthe first connecting portion, a plurality of nanoscale reflectors areformed on the second connecting portion, and shapes of nanoscalereflectors formed on the first connecting portion are different fromshapes of nanoscale reflectors formed on the second connecting portion.9. A semiconductor lighting module package, comprising: a lead framehaving a carrier portion, a first connecting portion and a secondconnecting portion; a first semiconductor lighting element and a secondsemiconductor lighting element located on the carrier portion andelectrically connected to the carrier portion and the first connectingportion and the second connecting portion respectively; and wherein aplurality of nanoscale reflectors are formed on the carrier portion, aplurality of nanoscale reflectors are formed on first connectingportion, and shapes of nanoscale reflectors formed on the carrierportion are different from shapes of nanoscale reflectors formed on thefirst connecting portion.
 10. The semiconductor lighting module packageof claim 9, wherein a plurality of nanoscale reflectors are formed onthe second connecting portions.
 11. The semiconductor lighting modulepackage of claim 10, wherein shapes of the nanoscale reflectors formedon the second connecting portion are different from shapes of thenanoscale reflectors formed on the first connecting portion.
 12. Thesemiconductor lighting module package of claim 10, wherein shapes of thenanoscale reflectors formed on the second connecting portion aredifferent from shapes of the nanoscale reflectors formed on the carrierportion.